This invention relates to a design of an automatic locking and releasing structure for a push-pull plug, particularly relates to a structural design for one where the conductive blades of the plug may be automatically locked in place and released to recover while adjusting the conductive blades to retract or extend.
It is found that the structural assembly of the conventional universal adaptor is provided with a plurality of sets of conductive blades of different configurations on the plug body, such that each set of conductive blades are embedded in the plug in a retracting or wrenching manner. Accordingly, the user may select one set of conductive blades in accordance with the power outlet specification at a desired country in using plug, while the remaining sets of conductive blades are concealed in the plug body. As such, the plug may be adapted to various power outlet specifications by adjusting the position of each set of the conductive blades.
The retracting structure of the conductive blades for the aforementioned universal adaptor (as shown in FIGS. 1 and 2) includes: conductive blades 10 provided on a slider 20; urging tabs 201 affixed to two sidewalls of the slider 20, such that the urging tabs 201 are able to act on push-buttons 30 provided on the outside of the slider 20 (as shown in FIG. 3), the push-buttons 30 being releasably engaged in slots 40 formed on the plug and restrained in place by a stop pieces 401 formed at the inside of the slots 40. When a user intends to adjust the state of the conductive blades 10, he needs to press the push-buttons 30 to disengage the push-buttons 30 from a state that is stopped and retrained by the stop pieces 401, to consequently cause displacement of the slider 20 driven by the push-buttons 30, such that when the conductive blades 10 are adjusted to the desired position, the user would release the force applying against the push-buttons 30 such that the push-buttons 30 are able to assume a state that urges against the stop pieces 401 under the influence of the urging tabs 201 (as shown in FIG. 4).
However, when the user does not understand the proper procedure for adjusting the conductive blades 10, he would intuitively and directly push and slide the push-buttons 30 to perform the adjusting operation. The intuitive operation would damage the stopping structure between each of the push-buttons 30 and stop pieces 401 as time passes to a least extent that would result in poor positioning of the conductive blades 10, or a severe extent that would result in complete malfunctions of the conductive blades 10.
In view of the shortcomings of the prior art, the inventor of this invention made improvements and invented an automatic locking and releasing structure for push-pull plug that is designed in consideration of the human factors and operational habits of the ordinary users, where the locking or releasing operations may be accomplished automatically while performing the adjusting operation by retracting/extending the conductive blades without damaging the structure.
The primary objective of this invention is to provide an automatic locking and releasing structure for a push-pull plug, where the conductive blades of the plug may be automatically locked in place and released to recover upon retracting or extending push-buttons.
To achieve this objective, this invention includes an upper case, a bottom case, a slider and push-buttons. The bottom case is suspended therein with two symmetrically arranged slide tracks that are each provided at the inside thereof with a wedge piece. The opposing sides of the slider are each formed with a resilient retaining arm, and the slider is movably provided between the two slide tracks. The free ends of the resilient retaining arms are movably attached to the push-buttons provided at the outside of the slide tracks. As such, when one manipulates the push-buttons to move along slide slots formed in the upper case and bottom case, the slider may be retracted or extended at the same time thereby subjecting the resilient retaining arms to assume a locking or releasing state with respect to the wedge pieces.
It is a further objective of this invention to provide an automatic locking and releasing structure for a push-pull plug, wherein the wedge pieces are each formed of an inclined configuration along the inside of the respective slide tracks such that when the slide tracks are driven by the slider to move upwards, the resilient retaining arms provided on opposing sides thereof are able to enter stopping faces formed on tops of the wedges piece along the inclined faces of the wedge pieces, subjecting the slider to be locked in place.
It is another objective of this invention to provide an automatic locking and releasing structure for push-pull plug, where the push-buttons are each formed on opposing sides of an urging plate thereof with inclined guide slots of an inclined configuration in such a manner that the inclined guide slots are correspondingly attached to opposing sides of the free ends of the resilient retaining arms, and capable of pushing the slider to move upwards. However, when the push-buttons slide downwards, the inclined guide slots are able to push the resilient retaining arms inwards to disengage from the stopping faces of the wedge pieces thereby releasing the slider.